There are many different ways to intermittently fast. From fasting throughout entire days alternately throughout the week, to only eating inside of an 8 hour window each day.
So how does it work for those trying to lose weight? Well, one reason intermittent fasting can aid in weight loss is down to how your body uses stored glycogen. When you eat carbohydrates for example, your body will convert the carbs into glycogen, which will then be stored in your muscles and liver, ready to be used as energy.
If your body burns through its glycogen stores, it will turn to stored body fat as its main source of energy. But, if it doesn’t burn through the glycogen before being topped up again, it will be stored as fat.
The average person will repeatedly be topping up their glycogen stores throughout the day, therefore their body never finds itself in requirement to use stored body fat for fuel. If, however, you follow an ‘intermittent fasting’ diet, your glycogen stores will be left empty for longer periods throughout each day, meaning your body will be left using your stored fat for fuel, instead of the energy that it would otherwise be getting from carbohydrates.
Now, this doesn’t mean we can just stuff our faces with whatever we want for 8 hours a day and expect to get lean. If you’re still consuming more calories in your eating window than you’re burning throughout the day, you’re going to gain weight. But due to people on an intermittent fasting diet having a a much smaller amount of time to eat on the average day, they’re much more likely to eat less food overall in comparison to someone who just eats consistently throughout the day.
On top of that, studies have shown that fasting can actually have a ‘blunting effect’ on hunger, resulting in fewer urges to snack or binge on food.
Health benefits of intermittent fasting
A number of studies (some of which are discussed in the above video) have shown intermittent fasting to result in a number of long term health benefits, such as reduced blood pressure and cholesterol in obese people, and has even shown to reduce depression.
Intermittent fasting is also shown to increase human growth hormone (HGH), which is great for muscle growth, recovery, reduced risk of cardiovascular disease, improved cognitive function and sleep quality.
The fact that intermittent fasting has been shown to improve insulin sensitivity, it may also be an attractive option for people with a BMI over 25, borderline diabetes or with type 2 diabetes, but not on blood sugar-lowering medications.
Will I lose muscle when intermittent fasting?
If you’re still getting enough protein in your diet and your workouts are in no way changing, there’s no reason for your muscle mass to decrease. Should intermittent fasting be a go-to diet for people wanting to maximise muscle growth? Probably not in comparison to a diet that is consistently fuelling your body throughout the day, due to smaller, consistent meals having more of an anabolic effect on the body, but it’s still very possible to build muscle whilst intermittent fasting.